The Study Of Optimal Concentration Of Carboplatin For Chemotherapy In Vitro And Apoptosis Induction On Tca8113

OBJECTIVESSquamous cell carcinoma is in majority of oral malignant tumor which is oftentreated by surgery, radiotherapy and chemotherapy clinically. Its survival rate in fiveyears is only about 40% partly because that medication still bases on citeratures andpersonal clinical experiences, and consequently the curative effects are not satisfied.Therefore, it is urgent to determine the optimal concentration of chemotherapeutics.This experiment is to explore optimal concentration of carboplatin for in vitrocell-killing and apoptosis induction on Tca8113 cells in different time intervals andstudy the mechanism of apoptosis in which the expressional ofhTERT involves.METHODS1 Tca8113 cells and HLF cells were added into different concentration ofdonor samples of carboplatin for 24h,48h,72h respectively, and the optimal cancercell-killed concentrations of carboplatin were obtained by MTT method.2 The cell morphous was observed by the inverted optical microscope; DNAladder was detected by abstracting DNA and agarose gel electrophoresis; apoptoticrate and cell cycle were obtained by FCM; the expression of hTERT was known byRT-PCR after 40μg/ml carboplatin on Tca8113 for 24h,48h,72h.RESULTSThe optimal concentration for Tca8113 cells killing in vitro in 24h,48h,72htime intervals are 120μg/ml,40μg/ml,30μg/ml respectively. Proliferation of Tca8113cells was inhibited by carboptatin and the proliferation index decreased significantlyas well. The apoptotic rate of cells treated with 40μg/ml carboplatin are 8.34%, 12.1%,12.6% in 24h,48h,72h time intervals. Cell cycle of Tca8113 was apparentlyarrested in S phases by carboplatin in time-depending manner. The expression ofhTERT was down-regulated in carboplatin-induced apoptotic cells.CONCLUSIONS1 In 24h,48h,72h time intervals, 120μg/ml,40μg/ml,30μg/ml were observedthe optimal concentrations for Tca8113 cells killing in vitro.Tca8113 cells weremostly killed by carboplatin while HLF survived in this concentration and the effectwas in time-depending manner.2 The proliferations of Tca8113 cells were significantly inhibited correlating tothe apoptosis induced by carboplatin.3 Tca8113 cell in S phase were increased significantly, implied that the cellcycle of Tca8113 was apparently arrested in S phases by carboplatin.4 The increasing apoptosis indicated inhitition of its expression of hTERTdepending on time at certain concentration.